if we say
X= Previous rate
then, the new rate is the previous rate + 5% of the previous rate:
23.61=X+5%X
5%= 5/100
so now we just solve the equation
[tex]\begin{gathered} 23.61=X+\frac{5}{100}X \\ 23.61=X\cdot(1+\frac{5}{100}) \\ 23.61=X\cdot\frac{21}{20} \\ 23.61\cdot\frac{20}{21}=X \end{gathered}[/tex]and X=22.48
So the answer is: Mary beth’s previous rate was 22.48